RockWoof
Check access before you go. Most sites listed here are old mines, quarries or prospects, and many are on private land or active mining claims. Get the landowner's permission, check the rules of the agency that manages any public land, and never enter mine workings. Locations are approximate.

Best regions by county

Ranked by the number of USGS-recorded sites, not by access or quality.

  1. Lehigh County: 254 sites; most recorded: Limonite, Magnetite, Molybdenite
  2. Berks County: 144 sites; most recorded: Magnetite, Limonite, Pyrite
  3. Northampton County: 110 sites; most recorded: Limonite, Slate, Molybdenite
  4. Westmoreland County: 92 sites
  5. Franklin County: 81 sites; most recorded: Limonite, Chromite

Top minerals

  • Limonite: 212 sites
  • Hematite: 61 sites
  • Magnetite: 37 sites
  • Slate: 11 sites
  • Chromite: 7 sites
  • Chalcopyrite: 5 sites
  • Pyrite: 5 sites
  • Molybdenite: 4 sites

Mineral cards

  • Copper

    Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat

    61 sites

  • Magnetite

    Mohs 5.5–6.5. Black and strongly magnetic. Mindat

    42 sites

  • Silver

    Mohs 2.5–3. Native silver tarnishes black. Mindat

    20 sites

  • Pyrite

    Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat

    14 sites

  • Mica

    Mohs 2–3. Peels into thin, flexible, shiny sheets. Mindat

    11 sites

  • Quartz

    Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat

    9 sites

  • Gold

    Mohs 2.5–3. Soft, heavy and bright yellow; it doesn’t tarnish. Mindat

    9 sites

  • Galena

    Mohs 2.5–2.75. Heavy, silvery lead ore that breaks into cubes. Mindat

    7 sites

  • Fluorite

    Mohs 4. Cubes in purple, green or yellow; many glow under UV. Mindat

    5 sites

  • Garnet

    Mohs 6.5–7.5. Usually deep red, round many-faced crystals. Mindat

    2 sites

Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.

Minerals most often recorded

Limonite 212Hematite 61Magnetite 37Slate 11Chromite 7Chalcopyrite 5Pyrite 5Molybdenite 4Calcite 3Wulfenite 2Quartz 2Barite 2

Counties

CountySites
Lehigh County254
Berks County144
Northampton County110
Westmoreland County92
Franklin County81
Chester County78
Cumberland County72
York County60
Huntingdon County48
Adams County48
Lancaster County47
Centre County44
Blair County37
Bedford County33
Bucks County20
Perry County20
Lawrence County20
Mifflin County19
Beaver County18
Allegheny County15
Delaware County12
Montgomery County12
Lebanon County10
Armstrong County9
Clarion County9
Union County8
Snyder County7
Clearfield County7
Columbia County6
Washington County6
Philadelphia County5
Fulton County (fewer than 5 sites, no page)4
Juniata County (fewer than 5 sites, no page)4
Butler County (fewer than 5 sites, no page)4
Susquehanna County (fewer than 5 sites, no page)4
Luzerne County (fewer than 5 sites, no page)3
Dauphin County (fewer than 5 sites, no page)3
Northumberland County (fewer than 5 sites, no page)3
Carbon County (fewer than 5 sites, no page)3
Erie County (fewer than 5 sites, no page)3
Clinton County (fewer than 5 sites, no page)3
Bradford County (fewer than 5 sites, no page)2
Montour County (fewer than 5 sites, no page)2
Cambria County (fewer than 5 sites, no page)2
Greene County (fewer than 5 sites, no page)2
Crawford County (fewer than 5 sites, no page)2
Tioga County (fewer than 5 sites, no page)2
Venango County (fewer than 5 sites, no page)2
Lycoming County (fewer than 5 sites, no page)2
Elk County (fewer than 5 sites, no page)2
Wayne County (fewer than 5 sites, no page)2
Mercer County (fewer than 5 sites, no page)1
Pike County (fewer than 5 sites, no page)1
Schuylkill County (fewer than 5 sites, no page)1
Monroe County (fewer than 5 sites, no page)1

Mineral guides

Related articles

How we built this page: we counted named sites in the USGS Mineral Resources Data System (MRDS) for this area, left out sand, gravel, crushed stone, clay pits and unnamed sites, grouped them by Census county, and linked every site to its USGS record. We did not visit these sites, and MRDS does not tell you who owns the land or whether collecting is allowed.

Source: USGS Mineral Resources Data System (MRDS). USGS ceased systematic updates to MRDS around 2011, so status and details may be out of date. Each site links to its USGS record.

Updated